Frankly, I think all oil & gas equities will be highly correlated regardless of where they are domiciled. So I would concentrate on an analysis of teh specific company itself (or just buy a sector ETF).
Yeah, everything is very highly corelated these days, especially when the commode hits the windmill. I am now heavily concentrated in 3 sectors: dry bulk shippers, retail depository institutions, and reinsurers. The first are dirt cheap and will continue to just print money as long as China and India keep growing (and they roll around in thousand dollar bills while India and China are trying to grow faster than the physical world permits). The second are cheaper than they have been in years and will be on fire whenever the Fed gets around to chopping rates (second half of the year is my guess). The third are damn cheap, and their performance will have very little to do with US or world economic trends.
Then I have some bonds and a grab-bag of one-off names.